1. Field of the Invention
The present general inventive concept relates to an image forming apparatus, and, more particularly, to an image forming apparatus, which can prevent contamination of an optical path between an exposure unit and an image carrier.
2. Description of the Related Art
Image forming apparatuses are devised to form an image on a printing medium according to an input image signal. Examples of image forming apparatuses include printers, copiers, facsimiles, and devices combining functions thereof
Of a variety of image forming apparatuses, an electro-photographic image forming apparatus includes a photosensitive member, an exposure unit, and a developing unit. The exposure unit scans light to the photosensitive member, which was charged with a predetermined electric potential, to form an electrostatic latent image on a surface of the photosensitive member. The developing unit supplies developer to the photosensitive member on which the electrostatic latent image is formed, to form a visible image.
The visible image, formed on the photosensitive member, is transferred to a printing medium transported from a printing medium feeding unit. The printing medium, to which the image is transferred, is discharged outside of the image forming apparatus after undergoing a fixing operation to fix the transferred image to the printing medium.
Generally, the exposure unit includes a housing having a light-transmission part, and a scanning optical system mounted in the housing. Light generated from the scanning optical system is emitted outside of the housing through the light-transmission portion. The emitted light is irradiated to the surface of the photosensitive member by passing through an optical path between the exposure unit and the photosensitive member, thereby forming the electrostatic latent image on the surface of the photosensitive member.
The image forming apparatus contains a variety of particles, including developer scattered from the photosensitive member and the developing unit, paper dust scattered from the printing medium, or dirt introduced from the outside. If the particles enter the optical path between the exposure unit and the photosensitive member, the particles prevent the light from being scanned to the photosensitive member, causing failure in the formation of the electrostatic latent image or deterioration of image quality.